158　be good at, be good for, be good to和be bad for

1　be good at 表示“善于，在……方面（做得，学得）好”。

He is good at physics. 他物理学得好。

We must be good at learning from others. 我们要善于向他人学习。

2　be good for 意为“对……有益，对……有用”。

Washing hands before meals is good for your health. 饭前洗手对健康有益。

The pill is good for a headache. 这种药对头痛有用。

3　be good to 意为“对……好”。

She is good to the old. 她待老人好。

4　be bad for 意为“有害于……”。

Reading in the sun is bad for your eyes. 在太阳底下阅读对眼睛不利。